One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10,14,17)(11,18,21,15)(12,16,13,22)(19,24,20,23)(25,26,29,32)(27,34,36,31)(28,38,30,33)(35,39,37,40)(9,11,14,21)(10,15,17,18)(12,19,13,20)(16,23,22,24)(25,27,29,36)(26,31,32,34)(28,37,30,35)(33,40,38,39)(2,5)(6,8)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,23,18,24)(26,32)(27,35)(28,30)(31,39)(34,40)(36,37)(1,3,4,7)(2,6,5,8)(9,13,14,12)(10,16,17,22)(11,20,21,19)(15,23,18,24)(26,32)(31,34)(33,38)(39,40)(11,21)(15,18)(19,20)(23,24)(25,28)(26,33)(27,36)(29,30)(32,38)(39,40) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.